Novel dual-action antimicrobial peptide may effectively manage caries: Study
According to a recent research published in the Journal of Dentistry, researchers have found out that novel dual-action peptide, GA-KR12, is potential applicable in the management of caries.
John YunNiu and colleagues from the Faculty of Dentistry, The University of Hong Kong, Hong Kong, China carried out the present study with the objective to develop a novel dual-action peptide with antimicrobial and mineralising properties.
A novel peptide, namely GA-KR12, was synthesised through grafting gallic acid to KR12. The secondary structure of GA-KR12 was evaluated by circular dichroism spectroscopy. The stability was evaluated by high-performance liquid chromatography.
The cytotoxicity was evaluated by a mitochondrial dehydrogenase activity assay. The antimicrobial properties against common cariogenic species were evaluated by minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC).
The morphology of cariogenic species was analysed by transmission electron microscope (TEM). To assess the mineralising effect of GA-KR12 on enamel, the lesion depths, mineral loss, surface morphology, calcium-to-phosphorus ratio and crystal characteristics were determined using micro-computed tomography, scanning electron microscopy (SEM) and energy dispersive spectroscopy X-ray diffraction, respectively.
The results showed that -
a. GA-KR12 did not exhibit cytotoxicity against HGF. Around 82% of the GA-KR12 remained in human saliva at 37°C for 1 h.
b. The MIC and MBC/MFC against the tested species were 10-320 μM and 20-1,280 μM, respectively. c. GA-KR12 induced remarkable morphological defects in the tested species.
d. The enamel treated with GA-KR12 had smaller lesion depths (p < 0.001), less mineral loss (p < 0.001) and higher calcium-to-phosphorus molar ratios (p < 0.001) than those in the enamel treated with water.
e. SEM showed a well-organised prism pattern in enamel treated with GA-KR12. X-ray diffraction revealed that the hydroxyapatite on the enamel treated with GA-KR12 was better crystalised.
Hence, the authors concluded that "this study developed a biocompatible and stable peptide which inhibited the growth of cariogenic species and mineralised the enamel caries."